Radiotherapy is a very commonly used anti-tumor treatment method. Generally, radiotherapy, together with chemotherapy and surgery, is listed as the three cornerstones of tumor treatment, so radiotherapy is better. However, it also depends on whether the patient is suitable for radiotherapy and the pathological characteristics of the patient’s tumor. There are some tumors that can be cured with radiotherapy, such as nasopharyngeal carcinoma and seminoma. Some other tumors have more lymph node metastases after radical surgery, in which case radiotherapy can prevent local recurrence. In this case, radiotherapy can prevent local recurrence and distant metastasis. There are also some tumors that are treated with chemotherapy and radiotherapy, which can also prevent local recurrence and distant metastasis. Radiotherapy is generally a kind of local treatment, which can shrink the tumor and prevent recurrence through radiation treatment.